Tree Susceptibility to Insect-Driven Disturbance
Climate models predict that disturbances for North American forests will likely be more frequent and intense as a result of anthropogenic climate change. A recent outbreak of a native insect, the red oak borer, in the forests of the Ozark Mountains of Arkansas and Missouri serves as a model for studying why some trees succumb to disturbances while others appear to remain healthy. Using a dendrochronological approach, we are examining patterns of tree growth in the decades prior to a destructive insect outbreak in these forests, in northern red oak trees that experienced mortality and those that survived. We are working in close collaboration with Dr. Fred Stephen at the University of Arkansas on this project. We are also examining carbon and oxygen isotopes in these tree-rings (δ 13C and δ 18O); these indices provide valuable information about tree carbon and water relations, and help us understand how different trees respond to insect-driven disturbances.